Difference between revisions of "Benzocaine"
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Revision as of 14:55, 27 January 2016
Benzocaine is a topical anesthetic that helps to numb the pain and itching. It's used as a topical pain reliever or in cough drops. Benzocaine combined with antipyrine forms A/B otic drops to relieve ear pain and remove earwax.
| IUPAC name
| Systematic IUPAC name
|C 9 H 11 NO 2|
|Molar mass||165.189 g/mol|
|Melting point||89 °C|
|Boiling point||310 °C|
|slightly soluble in water.|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Benzocaine is the ethyl ester of p-aminobenzoic acid (PABA). It can be prepared from PABA and ethanol by Fischer esterification or via the reduction of ethyl p-nitrobenzoate. Benzocaine is sparingly soluble in water; it is more soluble in dilute acids and very soluble in ethanol, chloroform and ethyl ether.
Benzocaine can be prepared by esterfication using 4-aminobenzoic acid and ethanol. It can also be prepared by reduction of ethyl 4-nitrobenzoate to the amine.
In industrial practice, the reducing agent is usually iron and water in the presence of a little acid.